class_docstr: Pie graph class
docstr: Draw all the serie slices
docstr_tok: ["Draw","all","the","serie","slices"]
code: def _plot(self):
      """Draw all the serie slices"""
      total = sum(map(sum, map(lambda x: x.values, self.series)))
      if total == 0:
          return
      if self.half_pie:
          current_angle = 3 * pi / 2
      else:
          current_angle = 0
  
      for index, serie in enumerate(self.series):
          angle = self.slice(serie, current_angle, total)
          current_angle += angle
  
file_path: pygal/pygal/graph/pie.py
imports: from math import pi
  from pygal.adapters import none_to_zero, positive
  from pygal.graph.graph import Graph
  from pygal.util import alter, decorate
label_desc: Use image node_id 4 for calling the Pie obj's underlying member method code with example usage: obj._plot() without return types